1. Field of the Invention
This invention relates to devices to lay down at least one plastic bead or the like onto an essentially plane surface of a part, particularly for the making of seals or seams to join another part.
2. Description of the Prior Art
Such devices are known in which pumps and guns are used which can extrude a plastic bead of a chosen diameter and at given speed which is in harmony with the relative movement between the gun and the part so as to lay down a uniform bead onto the part along a given trajectory.
In known devices, the gun is mounted onto a control system having two orthogonal axes (X and Y) whose motors respond to a programmed servo-control, or copy a model, while each part to be processed is fixed onto a fixing frame in a given position.
In certain devices, the movement of the gun along axes X and Y is accomplished by the shifting of cams specific to the work to be done, or by gauges and complex follower-rollers.
In the case of circular beads, the rotation of the part itself has already been proposed as a simpler and more advantageous technique than circular movement of the gun which, with its multiaxis shift control, requires a complex system that is heavy to manipulate, which is a drawback from the point of view of cost, place, weight, and rapidity of manipulation, making difficult a rapid pace of assembling a stream of parts to be processed.